Io was a priestess of the Goddess Hera in Argos, whose cult her father Inachus was supposed to have introduced to Argos. Zeus noticed Io, a mortal woman, and lusted after her. In the version of the myth told in Prometheus Bound she initially rejected Zeus' advances, until her father threw her out of his house on the advice of oracles. According to some stories, Zeus then turned Io into a heifer in order to hide her from his wife; others maintain that Hera herself transformed Io.
In the version of the story in which Zeus transformed Io, the deception failed, and Hera begged Zeus to give her the heifer as a present, which, having no reason to refuse, he did. Hera then sent Argus Panoptes, who had 100 eyes, to watch Io and prevent Zeus from visiting her, and so Zeus sent Hermes to distract and eventually slay Argus. According to Ovid, he did so by first lulling him to sleep by playing the panpipes and telling stories. Zeus freed Io, still in the form of a heifer.
In order to exact her revenge, Hera sent a gadfly to sting Io continuously, driving her to wander the world without rest. Io eventually crossed the path between the Propontis and the Black Sea, which thus acquired the name Bosporus (meaning ox passage), where she met Prometheus, who had been chained on Mt. Caucasus by Zeus. Prometheus comforted Io with the information that she would be restored to human form and become the ancestress of the greatest of all heroes, Heracles (Hercules). Io escaped across the Ionian Sea to Egypt, where she was restored to human form by Zeus.
Kontakt 
![Byzantion in Thracia, 500-300 BC., magistrate Kleo... , Æ19, Schönert-Geiss 963.
Byzantion in Thracia, magistrate Kleo... , ca. 500-300 BC.,
Æ19 (ø 18-19 mm / 6,38 g), brass, axes irregular alignment ↑↗ (ca. 50°),
Obv.: head of Demeter or Artemis Phosphoros (?) facing left.
Rev.: ΠY / {ME} / [EΠK]ΛE[Ω] , the heifer Io standing l. on a dolphin left, city label ΠY above, monogram ME under the raised forefoot in l. field, [magistrate´s title and name below].
E. Schönert-Geiss, Die Münzprägung von Byzantion I (1970) no. 963 pl. 40 and no. 974 pl. 41.
Io was a priestess of the Goddess Hera in Argos, whose cult her father Inachus was supposed to have introduced to Argos. Zeus noticed Io, a mortal woman, and lusted after her. In the version of the myth told in Prometheus Bound she initially rejected Zeus' advances, until her father threw her out of his house on the advice of oracles. According to some stories, Zeus then turned Io into a heifer in order to hide her from his wife; others maintain that Hera herself transformed Io.
In the version of the story in which Zeus transformed Io, the deception failed, and Hera begged Zeus to give her the heifer as a present, which, having no reason to refuse, he did. Hera then sent Argus Panoptes, who had 100 eyes, to watch Io and prevent Zeus from visiting her, and so Zeus sent Hermes to distract and eventually slay Argus. According to Ovid, he did so by first lulling him to sleep by playing the panpipes and telling stories. Zeus freed Io, still in the form of a heifer.
In order to exact her revenge, Hera sent a gadfly to sting Io continuously, driving her to wander the world without rest. Io eventually crossed the path between the Propontis and the Black Sea, which thus acquired the name Bosporus (meaning ox passage), where she met Prometheus, who had been chained on Mt. Caucasus by Zeus. Prometheus comforted Io with the information that she would be restored to human form and become the ancestress of the greatest of all heroes, Heracles (Hercules). Io escaped across the Ionian Sea to Egypt, where she was restored to human form by Zeus.
From https://en.wikipedia.org/wiki/Io_(mythology)
Schlüsselwörter: Byzantion Thracia magistrate Kleo Demeter Artemis Phosphoros heifer Io dolphin monogram forefoot](images/image.gif?id=1422509859004 "Klicken für Bild in voller Größe
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Byzantion in Thracia, 500-300 BC., magistrate Kleo... , Æ19, Schönert-Geiss 963.
Byzantion in Thracia, magistrate Kleo... , ca. 500-300 BC.,
Æ19 (ø 18-19 mm / 6,38 g), brass, axes irregular alignment ↑↗ (ca. 50°),
Obv.: head of Demeter or Artemis Phosphoros (?) facing left.
Rev.: ΠY / {ME} / [EΠK]ΛE[Ω] , the heifer Io standing l. on a dolphin left, city label ΠY above, monogram ME under the raised forefoot in l. field, [magistrate´s title and name below].
E. Schönert-Geiss, Die Münzprägung von Byzantion I (1970) no. 963 pl. 40 and no. 974 pl. 41.
Io was a priestess of the Goddess Hera in Argos, whose cult her father Inachus was supposed to have introduced to Argos. Zeus noticed Io, a mortal woman, and lusted after her. In the version of the myth told in Prometheus Bound she initially rejected Zeus' advances, until her father threw her out of his house on the advice of oracles. According to some stories, Zeus then turned Io into a heifer in order to hide her from his wife; others maintain that Hera herself transformed Io.
In the version of the story in which Zeus transformed Io, the deception failed, and Hera begged Zeus to give her the heifer as a present, which, having no reason to refuse, he did. Hera then sent Argus Panoptes, who had 100 eyes, to watch Io and prevent Zeus from visiting her, and so Zeus sent Hermes to distract and eventually slay Argus. According to Ovid, he did so by first lulling him to sleep by playing the panpipes and telling stories. Zeus freed Io, still in the form of a heifer.
In order to exact her revenge, Hera sent a gadfly to sting Io continuously, driving her to wander the world without rest. Io eventually crossed the path between the Propontis and the Black Sea, which thus acquired the name Bosporus (meaning ox passage), where she met Prometheus, who had been chained on Mt. Caucasus by Zeus. Prometheus comforted Io with the information that she would be restored to human form and become the ancestress of the greatest of all heroes, Heracles (Hercules). Io escaped across the Ionian Sea to Egypt, where she was restored to human form by Zeus.
From https://en.wikipedia.org/wiki/Io_(mythology)
Schlüsselwörter: Byzantion Thracia magistrate Kleo Demeter Artemis Phosphoros heifer Io dolphin monogram forefoot")